1 /*
2  * AD7879/AD7889 based touchscreen and GPIO driver
3  *
4  * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  *
8  * History:
9  * Copyright (c) 2005 David Brownell
10  * Copyright (c) 2006 Nokia Corporation
11  * Various changes: Imre Deak <imre.deak@nokia.com>
12  *
13  * Using code from:
14  *  - corgi_ts.c
15  *	Copyright (C) 2004-2005 Richard Purdie
16  *  - omap_ts.[hc], ads7846.h, ts_osk.c
17  *	Copyright (C) 2002 MontaVista Software
18  *	Copyright (C) 2004 Texas Instruments
19  *	Copyright (C) 2005 Dirk Behme
20  *  - ad7877.c
21  *	Copyright (C) 2006-2008 Analog Devices Inc.
22  */
23 
24 #include <linux/device.h>
25 #include <linux/init.h>
26 #include <linux/delay.h>
27 #include <linux/input.h>
28 #include <linux/interrupt.h>
29 #include <linux/irq.h>
30 #include <linux/slab.h>
31 #include <linux/spi/spi.h>
32 #include <linux/i2c.h>
33 #include <linux/gpio.h>
34 
35 #include <linux/spi/ad7879.h>
36 #include "ad7879.h"
37 
38 #define AD7879_REG_ZEROS		0
39 #define AD7879_REG_CTRL1		1
40 #define AD7879_REG_CTRL2		2
41 #define AD7879_REG_CTRL3		3
42 #define AD7879_REG_AUX1HIGH		4
43 #define AD7879_REG_AUX1LOW		5
44 #define AD7879_REG_TEMP1HIGH		6
45 #define AD7879_REG_TEMP1LOW		7
46 #define AD7879_REG_XPLUS		8
47 #define AD7879_REG_YPLUS		9
48 #define AD7879_REG_Z1			10
49 #define AD7879_REG_Z2			11
50 #define AD7879_REG_AUXVBAT		12
51 #define AD7879_REG_TEMP			13
52 #define AD7879_REG_REVID		14
53 
54 /* Control REG 1 */
55 #define AD7879_TMR(x)			((x & 0xFF) << 0)
56 #define AD7879_ACQ(x)			((x & 0x3) << 8)
57 #define AD7879_MODE_NOC			(0 << 10)	/* Do not convert */
58 #define AD7879_MODE_SCC			(1 << 10)	/* Single channel conversion */
59 #define AD7879_MODE_SEQ0		(2 << 10)	/* Sequence 0 in Slave Mode */
60 #define AD7879_MODE_SEQ1		(3 << 10)	/* Sequence 1 in Master Mode */
61 #define AD7879_MODE_INT			(1 << 15)	/* PENIRQ disabled INT enabled */
62 
63 /* Control REG 2 */
64 #define AD7879_FCD(x)			((x & 0x3) << 0)
65 #define AD7879_RESET			(1 << 4)
66 #define AD7879_MFS(x)			((x & 0x3) << 5)
67 #define AD7879_AVG(x)			((x & 0x3) << 7)
68 #define	AD7879_SER			(1 << 9)	/* non-differential */
69 #define	AD7879_DFR			(0 << 9)	/* differential */
70 #define AD7879_GPIOPOL			(1 << 10)
71 #define AD7879_GPIODIR			(1 << 11)
72 #define AD7879_GPIO_DATA		(1 << 12)
73 #define AD7879_GPIO_EN			(1 << 13)
74 #define AD7879_PM(x)			((x & 0x3) << 14)
75 #define AD7879_PM_SHUTDOWN		(0)
76 #define AD7879_PM_DYN			(1)
77 #define AD7879_PM_FULLON		(2)
78 
79 /* Control REG 3 */
80 #define AD7879_TEMPMASK_BIT		(1<<15)
81 #define AD7879_AUXVBATMASK_BIT		(1<<14)
82 #define AD7879_INTMODE_BIT		(1<<13)
83 #define AD7879_GPIOALERTMASK_BIT	(1<<12)
84 #define AD7879_AUXLOW_BIT		(1<<11)
85 #define AD7879_AUXHIGH_BIT		(1<<10)
86 #define AD7879_TEMPLOW_BIT		(1<<9)
87 #define AD7879_TEMPHIGH_BIT		(1<<8)
88 #define AD7879_YPLUS_BIT		(1<<7)
89 #define AD7879_XPLUS_BIT		(1<<6)
90 #define AD7879_Z1_BIT			(1<<5)
91 #define AD7879_Z2_BIT			(1<<4)
92 #define AD7879_AUX_BIT			(1<<3)
93 #define AD7879_VBAT_BIT			(1<<2)
94 #define AD7879_TEMP_BIT			(1<<1)
95 
96 enum {
97 	AD7879_SEQ_XPOS  = 0,
98 	AD7879_SEQ_YPOS  = 1,
99 	AD7879_SEQ_Z1    = 2,
100 	AD7879_SEQ_Z2    = 3,
101 	AD7879_NR_SENSE  = 4,
102 };
103 
104 #define	MAX_12BIT			((1<<12)-1)
105 #define	TS_PEN_UP_TIMEOUT		msecs_to_jiffies(50)
106 
107 struct ad7879 {
108 	const struct ad7879_bus_ops *bops;
109 
110 	struct device		*dev;
111 	struct input_dev	*input;
112 	struct timer_list	timer;
113 #ifdef CONFIG_GPIOLIB
114 	struct gpio_chip	gc;
115 	struct mutex		mutex;
116 #endif
117 	unsigned int		irq;
118 	bool			disabled;	/* P: input->mutex */
119 	bool			suspended;	/* P: input->mutex */
120 	u16			conversion_data[AD7879_NR_SENSE];
121 	char			phys[32];
122 	u8			first_conversion_delay;
123 	u8			acquisition_time;
124 	u8			averaging;
125 	u8			pen_down_acc_interval;
126 	u8			median;
127 	u16			x_plate_ohms;
128 	u16			pressure_max;
129 	u16			cmd_crtl1;
130 	u16			cmd_crtl2;
131 	u16			cmd_crtl3;
132 	int			x;
133 	int			y;
134 	int			Rt;
135 };
136 
ad7879_read(struct ad7879 * ts,u8 reg)137 static int ad7879_read(struct ad7879 *ts, u8 reg)
138 {
139 	return ts->bops->read(ts->dev, reg);
140 }
141 
ad7879_multi_read(struct ad7879 * ts,u8 first_reg,u8 count,u16 * buf)142 static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
143 {
144 	return ts->bops->multi_read(ts->dev, first_reg, count, buf);
145 }
146 
ad7879_write(struct ad7879 * ts,u8 reg,u16 val)147 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
148 {
149 	return ts->bops->write(ts->dev, reg, val);
150 }
151 
ad7879_report(struct ad7879 * ts)152 static int ad7879_report(struct ad7879 *ts)
153 {
154 	struct input_dev *input_dev = ts->input;
155 	unsigned Rt;
156 	u16 x, y, z1, z2;
157 
158 	x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
159 	y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
160 	z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
161 	z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
162 
163 	/*
164 	 * The samples processed here are already preprocessed by the AD7879.
165 	 * The preprocessing function consists of a median and an averaging
166 	 * filter.  The combination of these two techniques provides a robust
167 	 * solution, discarding the spurious noise in the signal and keeping
168 	 * only the data of interest.  The size of both filters is
169 	 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
170 	 * user-programmable conversion controls include variable acquisition
171 	 * time, and first conversion delay. Up to 16 averages can be taken
172 	 * per conversion.
173 	 */
174 
175 	if (likely(x && z1)) {
176 		/* compute touch pressure resistance using equation #1 */
177 		Rt = (z2 - z1) * x * ts->x_plate_ohms;
178 		Rt /= z1;
179 		Rt = (Rt + 2047) >> 12;
180 
181 		/*
182 		 * Sample found inconsistent, pressure is beyond
183 		 * the maximum. Don't report it to user space.
184 		 */
185 		if (Rt > ts->pressure_max)
186 			return -EINVAL;
187 
188 		/*
189 		 * Note that we delay reporting events by one sample.
190 		 * This is done to avoid reporting last sample of the
191 		 * touch sequence, which may be incomplete if finger
192 		 * leaves the surface before last reading is taken.
193 		 */
194 		if (timer_pending(&ts->timer)) {
195 			/* Touch continues */
196 			input_report_key(input_dev, BTN_TOUCH, 1);
197 			input_report_abs(input_dev, ABS_X, ts->x);
198 			input_report_abs(input_dev, ABS_Y, ts->y);
199 			input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
200 			input_sync(input_dev);
201 		}
202 
203 		ts->x = x;
204 		ts->y = y;
205 		ts->Rt = Rt;
206 
207 		return 0;
208 	}
209 
210 	return -EINVAL;
211 }
212 
ad7879_ts_event_release(struct ad7879 * ts)213 static void ad7879_ts_event_release(struct ad7879 *ts)
214 {
215 	struct input_dev *input_dev = ts->input;
216 
217 	input_report_abs(input_dev, ABS_PRESSURE, 0);
218 	input_report_key(input_dev, BTN_TOUCH, 0);
219 	input_sync(input_dev);
220 }
221 
ad7879_timer(unsigned long handle)222 static void ad7879_timer(unsigned long handle)
223 {
224 	struct ad7879 *ts = (void *)handle;
225 
226 	ad7879_ts_event_release(ts);
227 }
228 
ad7879_irq(int irq,void * handle)229 static irqreturn_t ad7879_irq(int irq, void *handle)
230 {
231 	struct ad7879 *ts = handle;
232 
233 	ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
234 
235 	if (!ad7879_report(ts))
236 		mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
237 
238 	return IRQ_HANDLED;
239 }
240 
__ad7879_enable(struct ad7879 * ts)241 static void __ad7879_enable(struct ad7879 *ts)
242 {
243 	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
244 	ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
245 	ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
246 
247 	enable_irq(ts->irq);
248 }
249 
__ad7879_disable(struct ad7879 * ts)250 static void __ad7879_disable(struct ad7879 *ts)
251 {
252 	disable_irq(ts->irq);
253 
254 	if (del_timer_sync(&ts->timer))
255 		ad7879_ts_event_release(ts);
256 
257 	ad7879_write(ts, AD7879_REG_CTRL2, AD7879_PM(AD7879_PM_SHUTDOWN));
258 }
259 
260 
ad7879_open(struct input_dev * input)261 static int ad7879_open(struct input_dev *input)
262 {
263 	struct ad7879 *ts = input_get_drvdata(input);
264 
265 	/* protected by input->mutex */
266 	if (!ts->disabled && !ts->suspended)
267 		__ad7879_enable(ts);
268 
269 	return 0;
270 }
271 
ad7879_close(struct input_dev * input)272 static void ad7879_close(struct input_dev* input)
273 {
274 	struct ad7879 *ts = input_get_drvdata(input);
275 
276 	/* protected by input->mutex */
277 	if (!ts->disabled && !ts->suspended)
278 		__ad7879_disable(ts);
279 }
280 
ad7879_suspend(struct ad7879 * ts)281 void ad7879_suspend(struct ad7879 *ts)
282 {
283 	mutex_lock(&ts->input->mutex);
284 
285 	if (!ts->suspended && !ts->disabled && ts->input->users)
286 		__ad7879_disable(ts);
287 
288 	ts->suspended = true;
289 
290 	mutex_unlock(&ts->input->mutex);
291 }
292 EXPORT_SYMBOL(ad7879_suspend);
293 
ad7879_resume(struct ad7879 * ts)294 void ad7879_resume(struct ad7879 *ts)
295 {
296 	mutex_lock(&ts->input->mutex);
297 
298 	if (ts->suspended && !ts->disabled && ts->input->users)
299 		__ad7879_enable(ts);
300 
301 	ts->suspended = false;
302 
303 	mutex_unlock(&ts->input->mutex);
304 }
305 EXPORT_SYMBOL(ad7879_resume);
306 
ad7879_toggle(struct ad7879 * ts,bool disable)307 static void ad7879_toggle(struct ad7879 *ts, bool disable)
308 {
309 	mutex_lock(&ts->input->mutex);
310 
311 	if (!ts->suspended && ts->input->users != 0) {
312 
313 		if (disable) {
314 			if (ts->disabled)
315 				__ad7879_enable(ts);
316 		} else {
317 			if (!ts->disabled)
318 				__ad7879_disable(ts);
319 		}
320 	}
321 
322 	ts->disabled = disable;
323 
324 	mutex_unlock(&ts->input->mutex);
325 }
326 
ad7879_disable_show(struct device * dev,struct device_attribute * attr,char * buf)327 static ssize_t ad7879_disable_show(struct device *dev,
328 				     struct device_attribute *attr, char *buf)
329 {
330 	struct ad7879 *ts = dev_get_drvdata(dev);
331 
332 	return sprintf(buf, "%u\n", ts->disabled);
333 }
334 
ad7879_disable_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)335 static ssize_t ad7879_disable_store(struct device *dev,
336 				     struct device_attribute *attr,
337 				     const char *buf, size_t count)
338 {
339 	struct ad7879 *ts = dev_get_drvdata(dev);
340 	unsigned long val;
341 	int error;
342 
343 	error = strict_strtoul(buf, 10, &val);
344 	if (error)
345 		return error;
346 
347 	ad7879_toggle(ts, val);
348 
349 	return count;
350 }
351 
352 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
353 
354 static struct attribute *ad7879_attributes[] = {
355 	&dev_attr_disable.attr,
356 	NULL
357 };
358 
359 static const struct attribute_group ad7879_attr_group = {
360 	.attrs = ad7879_attributes,
361 };
362 
363 #ifdef CONFIG_GPIOLIB
ad7879_gpio_direction_input(struct gpio_chip * chip,unsigned gpio)364 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
365 					unsigned gpio)
366 {
367 	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
368 	int err;
369 
370 	mutex_lock(&ts->mutex);
371 	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
372 	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
373 	mutex_unlock(&ts->mutex);
374 
375 	return err;
376 }
377 
ad7879_gpio_direction_output(struct gpio_chip * chip,unsigned gpio,int level)378 static int ad7879_gpio_direction_output(struct gpio_chip *chip,
379 					unsigned gpio, int level)
380 {
381 	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
382 	int err;
383 
384 	mutex_lock(&ts->mutex);
385 	ts->cmd_crtl2 &= ~AD7879_GPIODIR;
386 	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
387 	if (level)
388 		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
389 	else
390 		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
391 
392 	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
393 	mutex_unlock(&ts->mutex);
394 
395 	return err;
396 }
397 
ad7879_gpio_get_value(struct gpio_chip * chip,unsigned gpio)398 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
399 {
400 	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
401 	u16 val;
402 
403 	mutex_lock(&ts->mutex);
404 	val = ad7879_read(ts, AD7879_REG_CTRL2);
405 	mutex_unlock(&ts->mutex);
406 
407 	return !!(val & AD7879_GPIO_DATA);
408 }
409 
ad7879_gpio_set_value(struct gpio_chip * chip,unsigned gpio,int value)410 static void ad7879_gpio_set_value(struct gpio_chip *chip,
411 				  unsigned gpio, int value)
412 {
413 	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
414 
415 	mutex_lock(&ts->mutex);
416 	if (value)
417 		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
418 	else
419 		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
420 
421 	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
422 	mutex_unlock(&ts->mutex);
423 }
424 
ad7879_gpio_add(struct ad7879 * ts,const struct ad7879_platform_data * pdata)425 static int ad7879_gpio_add(struct ad7879 *ts,
426 			   const struct ad7879_platform_data *pdata)
427 {
428 	int ret = 0;
429 
430 	mutex_init(&ts->mutex);
431 
432 	if (pdata->gpio_export) {
433 		ts->gc.direction_input = ad7879_gpio_direction_input;
434 		ts->gc.direction_output = ad7879_gpio_direction_output;
435 		ts->gc.get = ad7879_gpio_get_value;
436 		ts->gc.set = ad7879_gpio_set_value;
437 		ts->gc.can_sleep = 1;
438 		ts->gc.base = pdata->gpio_base;
439 		ts->gc.ngpio = 1;
440 		ts->gc.label = "AD7879-GPIO";
441 		ts->gc.owner = THIS_MODULE;
442 		ts->gc.dev = ts->dev;
443 
444 		ret = gpiochip_add(&ts->gc);
445 		if (ret)
446 			dev_err(ts->dev, "failed to register gpio %d\n",
447 				ts->gc.base);
448 	}
449 
450 	return ret;
451 }
452 
ad7879_gpio_remove(struct ad7879 * ts)453 static void ad7879_gpio_remove(struct ad7879 *ts)
454 {
455 	const struct ad7879_platform_data *pdata = ts->dev->platform_data;
456 	int ret;
457 
458 	if (pdata->gpio_export) {
459 		ret = gpiochip_remove(&ts->gc);
460 		if (ret)
461 			dev_err(ts->dev, "failed to remove gpio %d\n",
462 				ts->gc.base);
463 	}
464 }
465 #else
ad7879_gpio_add(struct ad7879 * ts,const struct ad7879_platform_data * pdata)466 static inline int ad7879_gpio_add(struct ad7879 *ts,
467 				  const struct ad7879_platform_data *pdata)
468 {
469 	return 0;
470 }
471 
ad7879_gpio_remove(struct ad7879 * ts)472 static inline void ad7879_gpio_remove(struct ad7879 *ts)
473 {
474 }
475 #endif
476 
ad7879_probe(struct device * dev,u8 devid,unsigned int irq,const struct ad7879_bus_ops * bops)477 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
478 			    const struct ad7879_bus_ops *bops)
479 {
480 	struct ad7879_platform_data *pdata = dev->platform_data;
481 	struct ad7879 *ts;
482 	struct input_dev *input_dev;
483 	int err;
484 	u16 revid;
485 
486 	if (!irq) {
487 		dev_err(dev, "no IRQ?\n");
488 		err = -EINVAL;
489 		goto err_out;
490 	}
491 
492 	if (!pdata) {
493 		dev_err(dev, "no platform data?\n");
494 		err = -EINVAL;
495 		goto err_out;
496 	}
497 
498 	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
499 	input_dev = input_allocate_device();
500 	if (!ts || !input_dev) {
501 		err = -ENOMEM;
502 		goto err_free_mem;
503 	}
504 
505 	ts->bops = bops;
506 	ts->dev = dev;
507 	ts->input = input_dev;
508 	ts->irq = irq;
509 
510 	setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
511 
512 	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
513 	ts->pressure_max = pdata->pressure_max ? : ~0;
514 
515 	ts->first_conversion_delay = pdata->first_conversion_delay;
516 	ts->acquisition_time = pdata->acquisition_time;
517 	ts->averaging = pdata->averaging;
518 	ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
519 	ts->median = pdata->median;
520 
521 	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
522 
523 	input_dev->name = "AD7879 Touchscreen";
524 	input_dev->phys = ts->phys;
525 	input_dev->dev.parent = dev;
526 	input_dev->id.bustype = bops->bustype;
527 
528 	input_dev->open = ad7879_open;
529 	input_dev->close = ad7879_close;
530 
531 	input_set_drvdata(input_dev, ts);
532 
533 	__set_bit(EV_ABS, input_dev->evbit);
534 	__set_bit(ABS_X, input_dev->absbit);
535 	__set_bit(ABS_Y, input_dev->absbit);
536 	__set_bit(ABS_PRESSURE, input_dev->absbit);
537 
538 	__set_bit(EV_KEY, input_dev->evbit);
539 	__set_bit(BTN_TOUCH, input_dev->keybit);
540 
541 	input_set_abs_params(input_dev, ABS_X,
542 			pdata->x_min ? : 0,
543 			pdata->x_max ? : MAX_12BIT,
544 			0, 0);
545 	input_set_abs_params(input_dev, ABS_Y,
546 			pdata->y_min ? : 0,
547 			pdata->y_max ? : MAX_12BIT,
548 			0, 0);
549 	input_set_abs_params(input_dev, ABS_PRESSURE,
550 			pdata->pressure_min, pdata->pressure_max, 0, 0);
551 
552 	err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
553 	if (err < 0) {
554 		dev_err(dev, "Failed to write %s\n", input_dev->name);
555 		goto err_free_mem;
556 	}
557 
558 	revid = ad7879_read(ts, AD7879_REG_REVID);
559 	input_dev->id.product = (revid & 0xff);
560 	input_dev->id.version = revid >> 8;
561 	if (input_dev->id.product != devid) {
562 		dev_err(dev, "Failed to probe %s (%x vs %x)\n",
563 			input_dev->name, devid, revid);
564 		err = -ENODEV;
565 		goto err_free_mem;
566 	}
567 
568 	ts->cmd_crtl3 = AD7879_YPLUS_BIT |
569 			AD7879_XPLUS_BIT |
570 			AD7879_Z2_BIT |
571 			AD7879_Z1_BIT |
572 			AD7879_TEMPMASK_BIT |
573 			AD7879_AUXVBATMASK_BIT |
574 			AD7879_GPIOALERTMASK_BIT;
575 
576 	ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
577 			AD7879_AVG(ts->averaging) |
578 			AD7879_MFS(ts->median) |
579 			AD7879_FCD(ts->first_conversion_delay);
580 
581 	ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
582 			AD7879_ACQ(ts->acquisition_time) |
583 			AD7879_TMR(ts->pen_down_acc_interval);
584 
585 	err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
586 				   IRQF_TRIGGER_FALLING,
587 				   dev_name(dev), ts);
588 	if (err) {
589 		dev_err(dev, "irq %d busy?\n", ts->irq);
590 		goto err_free_mem;
591 	}
592 
593 	__ad7879_disable(ts);
594 
595 	err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
596 	if (err)
597 		goto err_free_irq;
598 
599 	err = ad7879_gpio_add(ts, pdata);
600 	if (err)
601 		goto err_remove_attr;
602 
603 	err = input_register_device(input_dev);
604 	if (err)
605 		goto err_remove_gpio;
606 
607 	return ts;
608 
609 err_remove_gpio:
610 	ad7879_gpio_remove(ts);
611 err_remove_attr:
612 	sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
613 err_free_irq:
614 	free_irq(ts->irq, ts);
615 err_free_mem:
616 	input_free_device(input_dev);
617 	kfree(ts);
618 err_out:
619 	return ERR_PTR(err);
620 }
621 EXPORT_SYMBOL(ad7879_probe);
622 
ad7879_remove(struct ad7879 * ts)623 void ad7879_remove(struct ad7879 *ts)
624 {
625 	ad7879_gpio_remove(ts);
626 	sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
627 	free_irq(ts->irq, ts);
628 	input_unregister_device(ts->input);
629 	kfree(ts);
630 }
631 EXPORT_SYMBOL(ad7879_remove);
632 
633 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
634 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
635 MODULE_LICENSE("GPL");
636